Point of use digital electric energy apparatus with uninterruptible telephone communication

ABSTRACT

A method and apparatus for providing uninterrupted telephone communication at a telephone customer site having an electrical energy monitoring apparatus connected to the customer site power distribution network. The method and apparatus monitor the voltage on the telephone network ring conductor to detect a voltage rise indicative of an incoming telephone call and determine whether or not the incoming telephone call is a normal telephone call or a data communication signal which is routed to the electric energy monitoring apparatus. A processor monitors the telephone network ring circuit to detect a voltage drop during data communication and, upon detecting a voltage drop, immediately switches communication to the customer telephone allowing normal operation of the customer telephone. Any data communication between the monitoring apparatus and a remote communication site is terminated and subsequently reinstituted.

CROSS REFERENCE TO CO-PENDING APPLICATION

[0001] This application claims the benefit of the filing date ofco-pending provisional U.S. Patent Application Serial No. 60/235,122,filed Sep. 25, 2000 and entitled “POINT OF USE DIGITAL ELECTRIC ENERGYMEASUREMENT, CONTROL AND MONITORING APPARATUS”.

BACKGROUND

[0002] The present invention relates, in general, to apparatus formeasuring and controlling the supply of electric energy at a use site.

[0003] In the electric utility industry, watthour meters are typicallyemployed to measure electric power used at a building or home site. Asocket housing is mounted on a convenient wall of the residence orcommercial building and contains pairs of line and load terminals whichare respectively connected to the electric utility line conductors andthe building load distribution conductors. The terminals typicallyreceive blade contacts on a plug-in watthour meter to complete anelectric circuit through the meter between the line and load terminals.

[0004] Plug-in socket adapters and socket adapters/extenders, bothhereafter referred to simply as socket adapters, are designed to pluginto the meter socket housing terminals. Such socket adapters areemployed to convert a ringless style socket to a ring style socket or toextend the mounting position of the jaw terminals in the socket outwardfrom the socket for mounting various electrical equipment, such as testdevices or survey recorders, in the socket. The watthour meter is thenplugged into jaw contacts carried within the socket adapter. The socketadapter jaw contacts are connected, either integrally or via separateelectrical connections, to blade terminals extending rearwardly of thesocket adapter housing for plug-in engagement with the socket terminalsor jaw contacts.

[0005] Meter reading personnel periodically inspect each meter site andrecord utility meter readings, either visually or by using a probe toretrieve power usage data stored in solid state memory of the watthourmeter.

[0006] To increase data collection efficiency and reliability, watthourmeters are now available which include interface equipment designed topermit remote interrogation of the meter and transmission of electricpower usage data. Utility meters located at each customer site areconnected in data communication to a central billing facility viavarious communication methods, including power line signal transmission,dedicated signaling lines, use of the public telephone switchingnetwork, and radio frequency signal transmission.

[0007] In automatic meter reading systems utilizing the existingtelephone network at each user site for communication between eachautomatic meter reader and the remote central site, it is imperativethat the automatic meter reading function be transparent to the customertelephone service. This means that the customer telephone service. Thismeans that the customer telephone service must be uninterrupted despiteany attempts to initiate or continue data communication between theautomatic meter reader and the remote central site.

[0008] Various telephone monitoring circuits have been devices tomonitor the state of the customer telephone so as to enable the customerto always receive or place a telephone call despite any ongoing datacommunication between the automatic meter reader and the central site.

[0009] However, it is believed that further improvements can be made tosuch automatic meter reader/telephone network interfaces which simplifythe telephone monitoring circuit and ensure that the customer'stelephone service is continually non-interrupted regardless of the stateof communications between the automatic meter reader and the centralsite.

SUMMARY

[0010] The present invention is a monitor circuit connected to a utilitycustomer telephone system in series and upstream of the customer'stelephone(s). The monitoring apparatus includes a processor executing acontrol program which monitors the voltage on the telephone network ringcircuit to detect a voltage rise indicative of an incoming telephonecall. Upon detecting a voltage rise, the processor determines whether ornot the incoming telephone call contains a data communication headersignal. The monitor apparatus controls the position of a switch to routethe detected incoming telephone call directly to the customer'stelephone or to the electric energy monitor apparatus depending uponwhether or not the incoming telephone call contains a data communicationheader signal.

[0011] If the incoming detected telephone call does not include a datacommunication header, the monitoring apparatus maintains the telephoneconnection switch to the customer's telephone allowing normal telephonecommunication via the customer's telephone system.

[0012] The processor, when executing the control program, also monitorsthe ring circuit voltage to detect a voltage drop during datacommunication. Immediately upon detecting voltage drop, the monitoringapparatus changes the position of the switch to reconnect the customer'stelephone to the telephone network for uninterrupted customer telephoneservice. The monitor apparatus discontinues the data communicationbetween the automatic meter reader remote and the remote meter centralsite.

[0013] It would also be desirable to provide an electric energymeasurement apparatus which is capable of utilizing communicationsthrough a global telecommunication network between the remote meterunits and a central site.

BRIEF DESCRIPTION OF DRAWINGS

[0014] The various features, advantages and other uses of the presentinvention are more apparent by referring to the following detaileddescription and drawing in which:

[0015]FIG. 1 is a schematic diagram of an electric energy managementapparatus according to the present invention;

[0016]FIG. 2 is an exploded, perspective view showing the electricenergy management apparatus according to the present invention mountablein a watthour meter socket;

[0017]FIG. 3 is a perspective view of the electric energy managementapparatus without the internal circuit board, the disconnect switch andthe shell;

[0018]FIG. 4 is a perspective view of the electric energy managementapparatus shown in FIG. 3 including the optional disconnect switch;

[0019]FIG. 5 is a side elevational view of the housing of the electricenergy management apparatus with a portion of the sidewall of thehousing removed to show the internal components of the electric energymanagement apparatus of the present invention;

[0020]FIG. 6 is a front elevational view of the circuit board of theelectric energy management apparatus shown in FIG. 5;

[0021]FIG. 7 is a block diagram of the major components of the electricenergy management apparatus at one customer use site;

[0022]FIGS. 8A, 8B, 8C, and 8D are detailed schematic diagrams of thecircuitry of the electric energy management apparatus mounted on thecircuit board shown in FIGS. 5 and 6;

[0023]FIGS. 9A and 9B are flow diagrams of the electric energymanagement apparatus control program;

[0024]FIG. 10 is a flow diagram of the power demand windows controlsequence of the present electric energy management apparatus;

[0025]FIG. 11 is a schematic diagram of the disconnect switch controlcircuitry used with the optional disconnect switch shown in FIG. 4;

[0026]FIG. 12 is a graph depicting out-of-specification voltages;

[0027]FIG. 13 is a flow diagram of the “out-of-spec” energy detectionsequence;

[0028]FIG. 14 is a flow diagram depicting the tamper detection sequence;

[0029]FIG. 15 is a side elevational view of the electric energymanagement apparatus depicting a partially removed position of thehousing from the meter socket;

[0030]FIG. 16 is a side elevational view, similar to FIG. 15, butshowing the housing blade terminals in a fully separated position withrespect to the socket jaw contacts;

[0031]FIG. 17 is a side elevational view of a meter installationdepicting the electric energy measurement apparatus of the presentinvention mounted in a ringless style meter socket;

[0032]FIG. 18 is a flow diagram of the telephone interrupt andnon-interrupt control sequence; and

[0033]FIG. 19 is a diagram of the optical communication circuit.

DETAILED DESCRIPTION

[0034] Referring now to the drawing, there is depicted a point of use,digital, electrical energy measurement, control and monitoring apparatusfor use at individual utility customer sites which has connectivitythrough a global telecommunication network to a centralized computercontrol system.

CENTRAL UTILITY

[0035] As shown in FIG. 1, a central utility company site is depictedgenerally by reference number 10. The central utility site 10 may be thecentral business office of the utility, a generating station, etc.,where utility billing information is accumulated, tabulated andrecorded. A central processing unit 12 is located at the central site10. The central processing unit 12 may be any suitable computer, such asa mainframe, a PC, a PC network, workstation, etc., having the capacityof handling all of the utility company customer billing transactionsand/or the remote data communications described hereafter. The centralprocessing unit 12 communicates with a memory 14 which stores,identification data specific to each utility customer, as well as otherdata regarding the power usage of each customer. The memory 14 mayinclude both hard disc storage memory and on-board memory. Although highvoltage, electrical power distribution lines denoted generally byreference number 16 for a three-wire, single-phase electrical system,are shown as extending between the central utility site 10 to eachutility customer 18, 19, etc., it will be understood that the electricalpower distribution lines 16 may extend from a separate electrical powergenerating site with appropriate voltage transformations to eachcustomer site, and not directly from the central utility site 10.Further, it will be understood that the electrical power distributionlines 16 may provide three-phase power to any customer site.

[0036] As shown in FIG. 1, various input and output devices, such akeyboard, printer(s) 13, display terminals or monitors 15, etc., mayalso be connected to the central processing unit 12 as is conventional.In addition, one or more modems 20 are connected to the centralprocessing unit 12 at the central utility site 10 and to a conventionaltelephone wiring network denoted generally by reference number 22. Thetelephone wiring network 22 may be conventional telephone wires, as wellas fiber optics, satellite, microwave, cellular telephone communicationsystems and/or combinations thereof. The modem 20, which may be anyconventional modem, functions in a known manner to communicate databetween a processor and the telephone network.

[0037] Also stored in the memory 14 are the various software controlprograms used by the central processing unit 12 to automaticallycommunicate with the electrical energy management apparatus at eachutility customer 18, 19 as described hereafter. The memory 14 alsostores the power usage data for each utility customer 18, 19 as well asvarious billing routines utilized by a particular utility company.

[0038] Generally, the software control program stored in the memory 14is a menu driven database capable of handling multiple simultaneouscalls to a number of remote apparatus at the customer sites 18, 19. Thecontrol program stores each customer's power usage in accumulated KWHand KVA, for example, and instantaneous voltage, current and powerfactor measurements. Also, the control program generates periodicsummary printouts via the printer 13.

[0039] The control program enables the utility to remotely program eachenergy management apparatus from the central site 10. Such programmablefeatures include time, date and year data, a multi-level security codefor communication access, receive call and originate call modes, linevoltage quality set points, start and end times for multiple demandbilling period intervals, i.e., three intervals in each 24 hour period,the date, time and duration of a communication window for communicationwith the central site 10, etc.

[0040] Various main system menu screens may be generated by the CPU 12to enable communication with any of the remote units. Further detailsconcerning the generation and use of such menu screens can be had byreferring to U.S. Pat. No. 5,590,179, the entire contents of which areincorporated herein by reference.

[0041] According to a unique feature of the present automatic meterreader apparatus, CPU 12 communicates with a global telecommunicationsnetwork that is separate from the conventional telephone line network 22through an interface including a modem connection 20 to an Internetservice provider (ISP) 20 which communicates with a worldwidetelecommunications network, such as the Internet or world wide web. TheCPU 12 can generate an appropriate identification number (I.D.) oraddress for any of the remote units. This I.D. can be transmitted by theISP 20 through the Internet 21 to any of the individual use sites 18,19, etc.

REMOTE UTILITY CUSTOMER

[0042] As shown in FIGS. 1 and 2, a plurality, such as tens or evenhundreds or thousands of utility customer sites 18, 19, are connected tothe electrical power distribution network 16 at remote locations ofvarying distances from the central utility company site 10.

[0043] As is conventional, each utility customer site 18, as shown inFIG. 1, includes a conventional utility meter socket 30 having aplurality of internally mounted jaw contacts or terminals 32 which areconnected to the single-phase three-wire line conductors of theelectrical distribution network 16. Although not shown in FIG. 1, theseparate jaw terminals 32 in the socket 30 are connected to theindividual service or load conductors at each utility customer site 18.In a conventional application, the socket 30 is mounted at a suitablelocation at the utility customer site 18, such as on an exterior wall,with the load conductors extending from the socket 30 to the buildingwiring circuits.

REMOTE UNIT

[0044] A digital, electric energy management apparatus (hereafter“remote unit”) 34 is provided for recording, measuring, controlling andmonitoring electrical power usage at a particular customer site 18. Theremote unit 34 has a plurality of outwardly extending, blade-type,electrical terminals 36 which electrically engage the jaw contacts orterminals 32 in the socket 30.

[0045] As shown in FIGS. 1 and 2, and in greater detail in FIGS. 3, 4and 5, the remote unit 34 of the present invention, in a preferredembodiment, includes a base denoted generally by reference number 40.The base 40 is snap-in connectable in the meter socket 30. However,according to the present invention, the base 40 includes internallymounted electrical energy measurement and telecommunication circuits asdescribed in greater detail hereafter. The use of the base 40 to housethe automatic meter reading circuitry is a preferred embodiment of thepresent invention. It will be understood, however, that such electricalenergy measurement and control circuitry, as described hereafter, canalso be mounted at each customer site 18, 19 by other means, such as inan enclosure separate from a standard watthour meter and the metersocket.

[0046] In general, the remote unit 34 includes a two-part housing formedof the base 40 having a base wall 42 and a shell 44 which are releasablyjoined together by a snap-in and rotate connection. As describedhereafter, a plurality of electrical terminals 34 are mounted in thebase 40. The electrical terminals 47 are provided in the base 40 in anynumber, type and arrangement depending upon the electrical power servicefor a particular application. By way of example only, the electricalterminals 47 are arranged in the base 40 in a first pair of lineterminals 54 and 56 and a second pair of load terminals 58 and 60.

[0047] A peripheral flange 48 is formed on the base 40 which mates witha similarly formed flange 33 on the watthour meter socket or housing 30for mounting the remote unit 34 to the watthour meter socket 30. Aconventional seal or clamp ring 62, such as a seal ring disclosed inU.S. Pat. No. 4,934,747, the contents of which are incorporated hereinby reference, is mountable around the mating flanges 48 and 33 tolockingly attach the remote unit 34 to the socket 30 and to preventunauthorized removal of or tampering with the remote unit 34.

[0048] It will also be understood that the remote unit 34 and the socket30 may be configured for a ringless connection. In this type ofconnection, not shown, the cover of the socket 30 is provided with anaperture which is disposable over the remote unit 34. The cover islocked to the socket 30 enclosure after the remote unit 34 has beeninserted in the socket 30 and through the aperture in the cover.

[0049] The base 40 and the base wall 42 has generally circularconfiguration centered within an integrally formed annular side wall 44which terminates in an outer edge 46. The flange 48 projects radiallyoutward from the sidewall 44 at the general location of the base wall42. A plurality of circumferentially spaced notches 50 are formed in theflange 48 for reasons which will be described in greater detail herein.

[0050] At least one and preferably two ground tabs 51, only one of whichis shown in FIG. 3, are mounted on the exterior surface of the base wall42 and have an radially outer end which is positioned within one of thenotches 51 as shown in FIG. 3. The ground tabs 51 are adapted to engagea ground connection in the meter socket 30, as is conventional and as isdescribed in greater detail hereafter.

[0051] The shell 44 has a generally cylindrical configuration formed ofa sidewall 45 and an end wall 53. An annular flange 47 projects radiallyfrom one end of the sidewall 45 as shown in FIGS. 2 and 5. The flange 47has a stepped shape formed of a radially extending leg and an axiallyextending leg. The flange 47 overlays the flange 48 on the base 40 andreceives the sealing ring 37 thereover as described above.

[0052] A plurality of arcuate slots 49, such as three slots 49 by way ofexample only, are formed in the radially extending leg of the flange 47.A generally L-shaped lock arm 51 projected interiorly from the radiallyextending leg of the flange 47 along one inside edge of each slot 49, asshown in FIG. 5. The L-shaped lock arm 51 is alignable with one of thenotches 51 in the base 40 when the shell 44 is joined to the base 40.Rotation of the shell 44 relative to the base 40 causes the lock arm 51to slide underneath the bottom edge of the flange 48 on the base 40 tolock the shell 44 to the base 40.

[0053] It will be understood that alignable apertures may be formed inthe flange 47 of the shell 44 and the flange 48 of the base 40 in therotated, locked position for receiving a seal member, such as aconventional watthour meter seal ring, not shown, to lockingly attachthe shell 44 to the base 40 and to provide an indication of tamperingwith the remote unit 34 after the remote unit 34 has been mounted on thesocket 30.

[0054] As also shown in FIGS. 1 and 2, and in greater detail in FIG. 5,the end wall 53 of the shell 44 is provided with an aperture 55 whichhas an under notch or undercut formed about the periphery of theaperture 55 as shown in FIG. 5. The aperture 55 is adapted for receivinga transparent cover 57, formed, by example, of Lexan, and having anotched peripheral edge which fits within the undercut formed about theperiphery of the aperture 55. A plurality of posts 59 project inwardlyfrom the undercut surrounding the aperture 55 in the end wall 53 of theshell 44 and are adapted to engage apertures formed about the peripheryof the cover 57 to align and mount the cover 57 to the end wall 53.Fasteners, such as lock nuts, not shown are mountable over the posts 59to lock the cover 57 in the end wall 53.

[0055] Although not shown in FIG. 5, portions of the transparent cover57 are masked or blacked out to provide separate windows, one for thedisplay 222 and one for the opto-communication port 134.

[0056] A plurality of apertures 52 are formed in the base wall 42 at thenormal jaw contact positions of a watthour meter. For the single phaseremote unit 34 described herein by way of example only, four apertures52 are formed in the base wall 42 and respectively received the lineblade terminals 54 and 56 and the load blade terminals 58 and 60. Theblade terminals 54, 56, 58 and 60 have one end portion disposedinteriorly within the base 40 extending away from one side of the basewall 42 and an external portion, shown in FIG. 5, which projectsexteriorly of the opposed surface of the base wall 42 and adapted toslidably engage the jaw contacts 32 in the watthour meter socket 30.

[0057] Although not shown, one of the apertures formed in the exteriorportion of each blade terminal 54, 56, 58 and 60 can receive a lockmember, such as a cotter pin, conventionally used in watthour meters, tofixedly secure each blade terminal 54, 56, 58 and 60 to the base wall44.

[0058] A plurality of bosses 62, such as three bosses by way of exampleonly, are formed on the base wall 42 and project therefrom to co-planarupper ends as shown in FIG. 5. Each boss 62 can be solid or hollow, buthas an upper end bore 64 adapted to receive a fastener, such as a screw,for securing a circuit board 66 containing the remote unit 34 circuitrythereon. Thus, the bosses 62 form a support for the circuit board 66 asshown in FIG. 5. This spaces the circuit board 66 above the bladeterminals 54, 56, 58 and 60 as well as above an optional disconnectswitch 70.

DISCONNECT SWITCH

[0059] The provision of a disconnect switch 70 is optional in the remoteunit 34 of the present invention. However, the disconnect switch 70provides valuable features when used in the tampering detect sequencedescribed hereafter. The disconnect switch 70 may also be remotelycontrolled by the central utility site 10 to control the power at aparticular customer site.

[0060] The disconnect switch 70 can be of conventional construction inthat it includes two switchable contacts, which are adapted to berespectively connected between one line and one load blade terminal,such as blade terminals 54 and 58 and 56 and 60.

[0061] To this end, the disconnect switch 70 is provided with a pair ofline terminals 72 and 74 which project outwardly from one side of thehousing of the disconnect switch 70 and a pair of load terminals 76 and78 which project from an opposite edge or surface on the disconnectswitch 70. The terminals 72 and 74 are adapted to be disposed inregistry with the load blade terminals 54 and 56 extending through thebase wall 42. Suitable fasteners, such as rivets, are employed tosecurely and electrically connect the terminals 72 and 74 to the loadblade terminals 54 and 56, respectively. Likewise, the load terminals 74and 78 are disposed in proximity with the load blade terminals 58 and 60and are secured thereto by means of suitable fasteners as describedabove. In this manner, the disconnect switch 70 can be easily mounted inthe base 42 without interfering with the circuit board 66.

[0062] Although the disconnect switch blade terminals 72, 74, 76 and 78have been described as being separate from the blade terminals 54, 56,58 and 60 in the base 40, it will be understood that the disconnectterminals 72, 74, 76 and 78 can be integrally formed as a one piece,unitary structure with the blade terminals 54, 56, 58 and 60 to form agenerally L-shaped blade terminal projecting from the disconnect switch70 which has an end portion, similar to the blade terminals 54, 56, 58and 60, which is slidingly engagable through one of the apertures in thebase wall 42.

[0063]FIG. 11 depicts the control circuitry for the disconnect switch 70which is mounted on a circuit board attached to the bottom surface ofthe circuit board 66 facing the disconnect switch 70. The disconnectswitch control circuitry includes a pair of flip-flops which rememberthe state of an internal relay in the disconnect switch 70. Theflip-flops enable the disconnect switch 70 contacts to be switched tothe last state after power is reapplied to the remote unit 34 after apower interruption, removal of the remote unit 34 from the meter socket30, etc.

[0064] The disconnect switch 70 may be controlled by a signal from thecentral site 10 to either “on” or “off” states as dictated by theelectric utility. The signal will be received by the circuit and causethe flip-flops to switch states in accordance with the on or off signal.At the same time, a push button 71, shown in FIG. 11, is mounted at aconvenient location on the shell 44 and the base 42 to enable acustomer, after receiving appropriate instructions from the electricutility, to manually reset the disconnect switch 70 to the “on” state.

REMOTE UNIT CIRCUITRY

[0065] A general block diagram and the circuitry of the major componentsof the remote unit 34 which are mounted in the base 40 at each utilitycustomer site 18 is shown in FIGS. 7, 8A-8D and 19. The circuit includesa power supply 122, voltage and current sensing circuit, an analog todigital conversion circuit 124, a central processing unit and associatedlogic 126, memories 128 and 129, a telephone communication modem 130, anopto-communication port 254, and a clock. The details of these majorcomponents will now be described.

[0066] As is conventional, the electrical power distribution network 16from the central utility company generating site typically carries 240VAC. A single-phase, three-wire power distribution network 16 is shownin FIGS. 1 and 2 with three wires connected to the electrical powerdistribution network 16 at each utility customer site 18. Each line 134and 136 carries 120 VAC RMS with respect to neutral or ground wire.

[0067] The power supply 122, shown in FIG. 8C, provides regulated, lowlevel DC power at the preferred ±DC levels required by the electroniccomponents used in the circuit 120.

[0068] The circuit 120 also includes a voltage sensing network denotedin general by reference number 180 in FIG. 8A. The voltage sensingnetwork receives 120 VAC RMS 60 Hz input from the utility lines. One setof voltage inputs including voltage lead line connections 182 and 183are between one lead line and neutral; while the other pair of inputs184 and 183 is between the other lead line conductor and neutral. Thevoltage lead 182 is input to a combination of series connected,differential amplifiers 185, 186 which have a settable gain of 1/100,for example. The output of the differential amplifiers is input to anA/D converter 124. The other line connection 184 is input to a similarcombination of differential amplifiers thereby resulting in two separatevoltage inputs as shown by reference numbers 190 and 191 in FIG. 8Awhich are connected to other inputs of the A/D converter 124. Thedifferential amplifiers 186 provide an instantaneous voltagecorresponding to the lead line voltage present on the conductors 182,183 and 184 which is within the input range of the A/D converter 124. Itshould be understood that the input voltages supplied to the A/Dconverter 124 are instantaneous voltages.

[0069] The current sensing network of the circuit 120 includes first andsecond current transformers 200 and 202, respectively, as shown in FIGS.3-5. The current transformers 200 and 202 each include a highpermeability toroid which is disposed around a circular wall 199surrounding each of the line blade terminals 54 and 56, respectively, inthe base 40. The circular wall 199 is preferably a continuous ordiscontinuous annular member or members which are fixedly disposed onthe base 40. Preferably, the wall 199 is integrally formed with andextends from the plane of the base 40.

[0070] The walls 199 provide a center support for the toroidal currenttransformers 200 and 202 to fixedly mount the current transformers 200and 202 on the base 40. This fixes the position of the currenttransformers 200 and 202 with respect to the inner disposed bladeterminals 54 and 56, respectively. Once the meter is calibrated, themagnetic flux between of the current transformers 200 and 202 and thecurrent flowing through the blade terminals 54 and 56 remains fixedthereby increasing the accuracy of the electric power measurement of themeter as compared to prior art automatic meter reader devices in whichthe current transformers are not held in a fixed position and arecapable of movement with respect to the blade terminals.

[0071] The current transformers 200 and 202 are precision, temperaturestable transformers which provide a ±10 volt output voltage signal inproportion to the instantaneous current flowing through the lineconductor. The electrical conductive coil of each current transformer200 and 202 maybe covered by a protective insulating coating, with theconductive coil leads or outputs extending therefrom.

[0072] The outputs 201 from the current transformer 200 are inputthrough a conditioning circuit to an amplifier 206. The output of thedifferential amplifier 206, which represents the scaled instantaneouscurrent in the line conductor 134, is supplied as an input to the A/Dconverter 124 as shown in FIG. 8A.

[0073] A similar signal conditioning circuit is provided for the currenttransformer 202. The output leads 203 from the current transformer 202are supplied to a differential amplifier 211. The output of thedifferential amplifier 211 is also supplied as a separate input to theA/D converter 124.

[0074] The A/D converter 124 includes internal sample and hold circuitsto store continuous voltage and current signal representations beforetransmitting such instantaneous voltage and current representations toother portions of the circuit 120, as described hereafter.

[0075] The twelve bit output from the A/D converter 124 is connected toan electronic programmable logic device (EPLD) 127, shown in FIG. 8A,which stores the instantaneous line voltages and currents and performsat least an initial kilowatt hour (KwH) calculation at the sample rateof the A/D converter 124 on each link. This gives a real time, dualchannel power measurement since the power on each separate 120 VAC lineand on the 240 VAC line is separately calculated. This avoids theaveraging employed in prior power metering devices and provides greaterpower measurement accuracy.

[0076] The individual line voltages and currents as well as thecalculated KwH are accumulated for a predetermined time period, beforethe data is transmitted through a high speed data bus to a centralprocessing unit 126. The central processing unit 126, in a preferredembodiment which will be described hereafter by way of example only, isa 16 bit microcontroller, Model No. AMI86ES, sold by Analog Devices. Themicrocontroller 126 executes a control program stored in the flashmemory 128, or backup EEPROM memory 129, as described hereafter, tocontrol the operation of the circuit 120. Clock signals from a real timeclock circuit 127, in FIG. 8B, are supplied to the processing unit 126and other circuit elements.

[0077] The microcontroller 126 also drives a display means 222, such asa liquid crystal display, for consecutively displaying for a brief timeinterval, for example, the total kilowatt hours (KwH) total KVA totaland KVA reactive, date, time, individual line current and voltage, andaverage power factor. The display 222 can be mounted, for example, at asuitable location on the circuit board 66, for easy visibility throughthe transparent cover 57 mounted in the end wall of the shelf 44. Thedisplay 222, in a preferred embodiment, contains 16 characters dividedinto significant digits and decimal digits.

[0078] Referring now to FIGS. 9A and 9B, there is depicted a flowdiagram of the sequence of operation of the control program executed bythe CPU 126. After initialization, the CPU 126 executes a number ofsteps to initialize various registers and to set up to receive voltageand current data. Maintenance routines are also executed to determine ifany of the components, such as the communication channels, the display226, etc., need service. If any maintenance or time event, such as azero crossing of the voltage or current waveforms is detected, the CPU126 executes the detected event step in a priority order from high tolow as shown in FIG. 9B which depicts an exemplary priority order ofevent processing.

TAMPER DETECTION

[0079] The remote unit 34 of the present invention is provided with aunique tamper detection circuit which not only detects at least one ormore different types of tamper events; but is capable of recording thetime of day and the total duration of the tamper event as well asoptionally taking action such as switching the disconnect switch 70 toan open condition thereby preventing any further application of electricpower through the disconnect switch 70 to the customer site 18, 19 whenthe remote unit 34 is reinserted into the socket 30.

[0080] The base 40 of the remote unit 34 is provided with at least oneand, preferably, two ground tabs 51, one being shown in FIG. 3, whichextend radially along the back surface of the base wall 42 into one ofthe notches 50 on the flange 48 surrounding the base wall 42. Eachground tab 51 is positioned to engage a ground connection in the socket30 to complete a ground circuit from the remote unit 34 through thesocket 30 to earth ground.

[0081] The tamper detection sequence of the present invention is basedon the mounting relationship of the blade terminals 54, 56, 58 and 60 inthe jaw contacts 32 in the socket 30 and the connection between theground tabs 51 and the mating ground tabs in the socket 30. In addition,the voltage and currents of each of the two legs or phases of powersupply to a customer use site 18 as well as the voltage and current ofthe center ground or neutral connection are continuously monitored aspart of the tamper detection.

[0082] Since the blade terminals 54, 56, 58 and 60 extend a distance,such as approximately ½ inch, into the jaw contacts 32 in the socket 30when in the full mounted position shown in FIG. 5, any attempt to removethe remote unit 34 from the socket 30 will initially cause the groundtab 51 to separate from the mating ground tab in the socket 30 in atimed sequence before the blade terminals 54, 56, 58 and 60 completelyseparate from the respective jaw contacts 32 and shown in FIGS. 15 and16.

[0083] In a normal operating state when the remote unit 34 is securelymounted in the socket 30, the voltage on the first and second legs willequal approximately 120 VAC, and the voltage and current on the groundleg will be zero. The current in the first and second legs will begreater than zero.

[0084] During a tamper event when the remote unit 34 is initially pulledfrom the socket 30, as shown in FIG. 15, the ground tab 51 will separatefrom the mating ground connection member in the socket 30. At this time,the ground current will equal zero while the voltage of the ground linewill be greater than zero due to the loss of ground connection. However,the blade terminals 54, 56, 58 and 60 are still connected to the socketjaw contacts 32 such that current continues to flow through the firstand second legs, i.e., i_(L1) and i_(L2)>0. Continued separation of theremote unit 34 from the socket jaws 32 will eventually completelyseparate the blade terminals 54, 56, 68 and 60 from the socket jawcontacts 32, as shown in FIG. 16, such that the current flowing throughthe first and second legs will drop to zero.

[0085] This defines the tamper signature detected by the remote unit 34of the present invention. Specifically, the tamper signature is thedetection of a time delay between the time that the ground currentequals zero and a ground voltage is greater than zero and a subsequenttime occurrence of at least one of the first and second line and loadcurrents equaling zero. In the case of a power outage, the groundvoltage will not be greater than zero, so as to not constitute thetamper signature.

[0086] This sequence is depicted in FIG. 14. The microprocessor, afterdetecting a tamper signature in step 127 will generate and send asignal, labeled “tamper” in FIG. 8B, to the disconnect switch 70 whichwill cause the disconnect switch 70 to switch or remain in an openposition the next time electric power is supplied to the disconnectswitch 70 through the blade terminals. This signal is shown by referencenumber 129. The CPU 126 also generates a notification signal 131 whichcan be transmitted back to the central site 10 to indicated to theutility that a tamper event has occurred. If the utility company choosesto contact the customer at the customer site at which a tamper event wasdetected, the utility company can notify the customer that tampering hasbeen detected and provide the customer with the time of the start of thetamper detection as well as the total duration of the tamper event.Corrective action can now be easily taken by the utility to address thetamper event.

[0087] Upon reconnecting power to the offending customer site, thecentral site 10 can send a signal through the communication networkdescribed hereafter, to the customer site to set up the disconnectswitch circuitry to reapply power to the disconnect switch 70 after thecustomer pushes pushbutton 71 on the remote unit 34. This will cause thedisconnect switch 70 contacts to switch to the closed state therebyreconnecting a circuit between the line and load blade terminals in theremote unit 34.

[0088] The signal 131 also contains data relating to the time and dateof the start of the detected tamper signature event as well as the timeduration of the tamper event. The time and date of the start of thetamper event as well as the duration of the each detected tamper eventcan be stored in the memory of the remote unit 34 for later transmissionto the central site 10 for tamper event recordation, analysis, etc.

[0089] Instead of a control program consisting of software instructionsexecuted by a microprocessor, the above described tamper event detectionmethod can also be implemented in a dedicated electronic circuit formedof electric current and voltage sensors and logic elements which cansense the line and ground circuit voltages and currents as well as atime separation between certain voltages and currents as describedabove. The outputs of such a circuit can be the“tamper” signal which canbe transmitted by various means, such as power line communication, Rfcommunication, etc., to a central site 10. The “tamper” signal can beapplied directly to the disconnect switch 70 to automatically disconnectthe supply of electric power to the meter site at which a tamper eventhas been detected.

[0090] In FIG. 18, the remote unit 34 of the present invention is shownmounted in a ringless style watthour meter socket 400 which includes ahousing 402 and a cover 404. A raised annulus 406 is formed in the cover404 surrounding an aperture 408 through which the sidewall of the remoteunit 34 extends.

[0091] Inner disposed mounting brackets 410 and 412, which are fixedlymounted on the sidewalls of the socket housing 402, extend inward to aninner flange end 414. The inner flange end 414 is positioned to engageone of the ground tabs 51 extending radially outward on oppositediametric sides of the housing of the remote unit 34. This completes aground circuit through the internal circuitry of the remote unit 34 andthe earth ground connection in the meter socket 400.

[0092] The tamper event signature detection method and apparatusaccording to the present invention takes place in the same manner asthat described above.

REMOTE COMMUNICATIONS

[0093] A first communication feature of the remote unit 34 of thepresent invention is uninterruptible telephone service to the customersite 18. The remote unit 34 intercepts calls by TCP/IP modem interfacecircuitry that permits the remote unit 34 to answer incoming calls fromthe central site 40 without detection by the customer, and,additionally, a courtesy transfer feature that automatically disconnectsthe remote unit 34 from the telephone line and prepares the remote unit34 for a later retry when the customer picks up the handset on thetelephone during a communication between the remote unit 34 and thecentral site 10

[0094] The uninterruptible telephone service is achieved by connectingthe TCP/IP modem interface circuit in series in the telephone(s) of theuse site 18. In this manner, the remote unit 34 can recognize andintercept the ring circuit to receive or transmit data to the centralsite 10.

[0095] Initially, the CPU 126 detects a voltage rise before a voltagepeak is reached in the ring circuit. The CPU 126 is programmed torecognize the TCP/IP data format from the central site 10. Upondetecting the TCP/IP format, the CPU 126 routes the incoming telephonecall to the appropriate part of the remote unit circuitry 120 forprocessing and prevents the incoming call from reaching the customer'stelephone thereby preventing ringing of the customer's telephone.

[0096] At the same time, the CPU 126 monitoring the ring circuit for avoltage drop which occurs when the customer picks up the handset of oneof its telephones. Upon detecting the voltage drop, the CPU 126immediately disconnects the telephone ring connection through the modem130 and switches the connection to the customer's telephone therebyallowing the customer to make an outgoing call without interruption fromthe remote unit 34.

[0097] Referring now to FIG. 18, there is depicted the control programsequence for operation of the remote communication interface to theremote unit 34 and telephone service to the customer site 18.

[0098] As shown in FIGS. 1 and 8D, the customer site 18 is provided witha switch 300 which is embodied internally within a programmable modemcircuit 302 shown in FIG. 8D. The programmable modem 302 executes afirmware control program which maintains the switch 300 in the normallyclosed position for normal telephone communication on the telephonenetwork conductors to and from the customer's telephone(s) 304.

[0099] As shown in FIG. 8B, the tip and ring conductors of the telephonenetwork are connected to a header or jack 306 which provides inputconnections to the modem 302 as shown in FIG. 8D. The switch 300, shownin a pictorial representation in FIG. 1, is normally closed therebyproviding a connection of the tip and ring circuits on leads 308 to thecustomer's telephone 304. This is embodied in control step 310 in FIG.18.

[0100] The modem 302 is programmed to continuously monitor the ringvoltage in step 312 to detect a voltage rise from the nominal ringvoltage associated with a non-call condition. Such a voltage rise is anindication of an incoming telephone call on the ring conductor. Upondetecting a voltage rise in the ring conductor or circuit in step 314,the modem 302 then looks at the following data signals to detect acommunication signal header format indicating a data communicationsignal from the central site 10. As noted above, this communicationformat can be the standard Internet TCP/IP communication protocol.

[0101] If the data communication header format is not detected in step316 following a detection of a voltage rise in step 314, the modem 302maintains the switch 300 in a closed position as shown in step 318thereby allowing the normal incoming telephone call to be connected tothe customer's telephone 304. This allows the customer to conduct anormal two-way telephone call without interference from the remote unit34.

[0102] Alternately, if the modem 302 detects the data communicationheader format in step 316, the modem 302 opens the switch 300 in step320 and establishes data communication between the central site 10 andthe remote unit 34 in step 322.

[0103] The modem 302 continuously monitors the bidirectional datacommunication in step 324 to determine when the data communication iscompleted or finished. Upon completion of the data communicationexchange, the modem 302 will reclose the switch 300 in step 326.

[0104] As shown in FIG. 18, continuously during the data communicationsequence, the modem 302 monitors the ring voltage which has previouslyrisen to a voltage peak during a telephone or data communication. If thecustomer picks up the handset of the telephone 304 during the datacommunication sequence, the ring voltage will drop. The modem 302, bycontinuously monitoring the ring voltage in step 330 will detect thevoltage drop from the voltage peak in step 332. Immediately upondetecting a voltage drop in step 332, the modem 302 terminates the datacommunication between the remote unit 34 and the central site 10 in step334 and recloses the switch 300 in step 326 to enable the customer tocomplete the telephone call.

[0105] The remote unit CPU will store a flag indicating that datacommunication was interrupted and will restart or reconnect the remoteunit 34 with the central site at a later time or date to complete thedata communication sequence which was interrupted.

[0106] The same non-interruptible telephone service to the customer alsoapplies when the processing unit 126 initiates a data communication tothe central site 10. The modem 302 will initiate a telephone call whichwill drive the ring voltage to a high voltage level. The processor inthe modem 302 will continuously monitor the ring voltage during the datacommunication to and from the central site 10 to detect a voltage dropwhich will occur if the customer picks up the handset of the telephone304. In a manner similar to steps 330, 332, 334, and 336 in FIG. 18 anddescribed above, the processor in the modem 302 will immediatelyterminate data communication and reclose the switch 300 to enable thecustomer to complete a telephone call in a normal, non-interruptedmanner. The processor of the modem 302 can supply a signal or flag tothe processor 126 in the automatic meter reader 34 to indicate that datacommunication was interrupted. The automatic meter reader 34 will, at alater program time, reinitiate data communication to the central unit toretransmit all stored power values.

[0107] Another communication feature is the use of global networkcommunications via TCP/IP protocol through the modem 302. This enableseach remote customer site 18, 19, etc., to exchange data with thecentral utility site 10 over a global network, such as the Internet 21,in digitally encoded TCP/IP protocol at random time based intervals. Thecommunication is two-way frequency programmable as well as durationprogrammable to permit communication flexibility. Each reader 34 willhave an Internet address for unique communication with the central site10.

[0108] The modem 302 at each customer use site as well as the modem inthe central site 10 provides one way of connection to a globaltelecommunication network, such as the Internet or World Wide Web. Itwill be understood that other interfaces or connections to the globaltelecommunication network may also be employed, such as a direct cableconnection, direct subscriber line connection, etc.

[0109] Another communication feature is wireless communication via acordless or wireless optical communications port 254. An opticalreceiver, preferably an infrared receiver (IR) in the form of a pair ofphotodiodes or LED's 257 is mounted on the circuit board 66 and has afield of view through transparent cover 57 to receive optical orinfrared signals from a wireless infrared programmer, not shown. Theinfrared programmer can be a hand held unit, computer lap top, orcomputer integrated infrared wand having an IR transmitter to enable autility service person to program, upload and download information,connect and disconnect service via the disconnect switch 70, andinstantaneously obtain customer load profile, use and serviceinterruption data.

[0110] The photodiodes 257 are mounted on an integrated circuit 256which carries connections to the ASIC circuit 255 for controlling thetransmit and receive data communication through the photodiodes 257 at aclock rate established by a crystal oscillator 258 input to the ASICcircuit 255. Input and output leads are connected between the ASICcircuit 255 and the central processor 126. The CPU 126, under storedprogram control, is capable of receiving and decoding input signalsreceived by the photodiodes 257 as well as transmitting data in thedesired format through one of the photodiodes 257 to the externalprogrammer.

[0111] The unique wireless communications port simplifies theconstruction of the remote unit 34 since a plug connection to anexternal programmer, as previously required, is no longer necessary.

OUT-OF-SPEC POWER

[0112] As described above, an electric utility is required to deliverelectrical power, particularly the voltage of such power, within aspecified range of maximum and/or minimum voltages. For example, thesupplied voltage cannot exceed 120 VAC RMS or be below 114 VAC RMS.

[0113]FIG. 12 depicts an exemplary voltage versus time waveform ofelectrical power supplied to customer site 18. TOD1 depicts the start ofan out of range voltage excursion on leg or phase one of the electricpower delivered to the customer use site 18. The remote unit 34 detectsthe out of range excursion of the instantaneous voltage on leg onebeyond the high voltage limit, and stores the time of day (TOD1) of thebeginning of the out-of-spec voltage excursion as well as of theduration 301, or the total length of time that the voltage isout-of-spec. This time duration is converted to kilowatt hours in realtime as shown in FIG. 13 to provide an indication of the amount ofout-of-spec power which was delivered to a particular use site.

[0114]FIG. 12 also depicts a low voltage out-of-spec excursion. Thestart time TOD2 and the duration 303 of this excursion are also detectedand stored in the memory of the remote unit 34 and the kilowatt hours oflow “out-of-spec” voltage is determined. In this manner, a utility candetermine whether or not electric power was delivered to a particularuse site outside of the required range.

[0115] As shown in FIG. 13, when a upper RMS voltage limit is exceededon any of the lines in step 305, the CPU 126 monitors the RMS voltagefor the duration of the upper limit excursion in step 306. The CPU 126via the EPLD 27 calculates the “out-of-spec” energy use during the upperlimit excursion in step 308. This “out-of-spec” energy use isaccumulated in kilowatt hours in real time in step 310. A similarsequence is used when the lower voltage RMS limit is exceeded in step312. As described above, the CPU 126 monitors the RMS voltage during thelower limit excursion in step 314 and calculates the total “out-of-spec”energy use in kilowatts below the legal voltage limit in step 316. Theout-of-spec low voltage and kilowatt hours are accumulated in real timein step 318 for transmission to the cental site 10 for billing purposes.

POWER DEMAND WINDOWS

[0116] As describe above, the CPU 126 through the voltage and currentdetection circuitry 120 is capable of measuring and storing theinstantaneous line voltages in the calculated KwH and other electricpower parameters at each sample of the A/D converter 124.

[0117] The CPU 126 operates on a demand window concept wherein each 24hour day is divided into a plurality of intervals of any predeterminedduration, such as 15 minutes, 30 minutes, 45 minutes, 60 minutes, etc.In each interval, the total KwH, KAV, average phase angle, and peakvoltage and current variables are calculated and stored in the memory128. This data can be transmitted to the central site at any time uponreceipt of an interrogation signal from the central site 10 or on a timesequence initiated by the remote unit 34.

[0118] This interval arrangement allows peak voltage and currentexcursions on any of the power lines at a customer site to be detectedand reported. Previously, the average of the voltage and currentsupplied to a particular customer site were used thereby rendering thecentral utility incapable of detecting any peak voltages or currents.

[0119] As shown in FIG. 10, in order to provide different real timepricing for peak utility demand periods, week days, weekends, holidays,etc., the control program of the CPU 126 is provided with a plurality ofdiscrete schedules, such as sixteen schedules by example only. Three ofthe schedules are shown in FIG. 10, again by example. The first scheduleprovides for regular time (non-daylight savings time) wherein the powerusage data is stored and transmitted on a weekly basis. As shown in step400, the weekly data storage can also be subdivided into two differentday schedules, one for week days and one for weekends. Up to twenty fourwindows per day are provided for each day schedule. At the end of anyday schedule time period, the CPU 126 automatically switches to theother day schedule.

[0120] Similarly, the CPU 126 is programmed to automatically switch to adaylight savings time schedule as shown in step 402. This can also be ona weekly recurring data reporting basis. This schedule is divided intothree days schedules, by example only, covering the weekdays,(Monday-Friday), a separate Saturday schedule and a separate Sundayschedule. Each day schedule is subdivided into twenty four windows perday, with the sequence automatically switching to the next sequentialday schedule at the completion of the then current day schedule.

[0121] Finally, a holiday schedule is depicted in step 404 which isprovided on a daily basis.

What is claimed is:
 1. A method for transferring data over a telephonenetwork having tip and ring circuits one of a customer telephone and anelectrical energy monitoring apparatus, the method comprising the steps:connecting a utility electrical energy monitoring apparatus in seriesand upstream of the customer's telephone in the customer's telephonenetwork; connecting a switch in series with the customer's telephone andthe customer's telephone network, the switch having first and secondpositions, the first position connecting the customer's telephone to thetelephone network and the second position connecting the telephonenetwork to the monitoring apparatus at the customer's site; sensing avoltage rise on the telephone network indicating an incoming telephonecall on a telephone network to the customer site; determining if a datacommunication header signal is present on the incoming telephone call;if data communication header signal is present, switching the switch tothe second position connecting the monitoring apparatus in datacommunication with the telephone network; and if the data communicationheader signal is absent, maintaining the switch in the first position toallow telephone communication with the customer's telephone.
 2. Themethod of claim 1 further comprising: during data communication with themonitoring unit at a customer site, monitoring the voltage on thetelephone network ring circuit to detect a voltage drop caused by theremoval of a telephone handset from the customer's telephone; and upondetecting a voltage drop in the telephone ring circuit, moving theswitch to the first position reestablishing communication between thetelephone network and the customer telephone, and disconnecting datacommunication to the electric energy monitoring apparatus at thecustomer site.
 3. An electrical energy monitoring apparatus fortransferring data over a telephone network having tip and ring circuitsconnected to a customer telephone at a customer site, the apparatuscomprising: a switch adapted to be connected in series and upstream ofthe customer's telephone in the telephone network, the switch movableunder program control between a first position establishing telephonecommunication between the customer telephone and the telephone networkand a second position establishing data communication between thetelephone network and the electric energy monitoring apparatus; aprocessor under program control for monitoring the voltage on thetelephone network ring conductor to detect a voltage rise indicative ofan incoming telephone call on the telephone network; and the processor,under program control, detecting whether or not a data communicationformat header signal is part of the incoming telephone call and, if theheader signal is present, moving the switch to the second positionestablishing data communication between the telephone network and theprocessor.
 4. The apparatus of claim 3 further comprising: theprocessor, under program control, monitoring the ring circuit of thetelephone network for a voltage drop during data communication; and upondetecting a voltage drop in the telephone ring circuit, the processormoving the switch to the first position establishing telephonecommunication between the customer telephone and the customer telephonenetwork.